Andrews, T, Smith, CJ orcid.org/0000-0003-0599-4633, Myhre, G et al. (3 more authors) (2021) Effective radiative forcing in a GCM with fixed surface temperatures. Journal of Geophysical Research: Atmospheres, 126 (4). ISSN 2169-897X
Abstract
Effective radiative forcing (ERF) is evaluated in the ACCESS1.0 General Circulation Model (GCM) with fixed land and sea‐surface‐temperatures as well as sea‐ice. The 4xCO2 ERF is 8.0 Wm‐2. In contrast, a typical ERF experiment with only fixed sea‐surface‐temperatures (SST) and sea‐ice gives rise to an ERF of only 7.0 Wm‐2. This difference arises due to the influence of land warming in the commonly used fixed‐SST ERF experimental design, which results in: (i) increased emission of longwave radiation to space from the land surface (‐0.45 Wm‐2) and troposphere (‐0.90 Wm‐2), (ii) reduced land snow‐cover and albedo (+0.17 Wm‐2), (iii) increased water‐vapour (+0.49 Wm‐2), and (iv) a cloud adjustment (‐0.26 Wm‐2) due to reduced stability and cloudiness over land (positive ERF) counteracted by increased lower tropospheric stability and marine cloudiness over oceans (negative ERF) . The sum of these radiative adjustments to land warming is to reduce the 4xCO2 ERF in fixed‐SST experiments by ∼1.0 Wm‐2. CO2 stomatal effects are quantified and found to contribute just over half of the land warming effect and adjustments in the fixed‐SST ERF experimental design in this model. The basic physical mechanisms in response to land warming are confirmed in a solar ERF experiment. We test various methods that have been proposed to account for land warming in fixed‐SST ERFs against our GCM results and discuss their strengths and weaknesses.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021. Crown copyright. Journal of Geophysical Research: Atmospheres published by Wiley Periodicals LLC on behalf of American Geophysical Union. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland. This is the peer reviewed version of the following article: Andrews, T, Smith, CJ, Myhre, G et al. (3 more authors) (2021) Effective radiative forcing in a GCM with fixed surface temperatures. Journal of Geophysical Research: Atmospheres, 126 (4). ISSN 2169-897X, which has been published in final form at 10.1029/2020jd033880. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. |
Keywords: | Radiatve forcing; Fixed‐SST; Land warming; GCM; Radiative Effects |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) NE/T009381/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Feb 2021 15:58 |
Last Modified: | 05 Aug 2021 00:38 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1029/2020jd033880 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:171015 |